* Soy, corn bounce after hitting lowest in three years

* Cheap Russian exports depress wheat

HAMBURG, Feb 12 (Reuters) - Chicago soybeans and corn rose on Monday on bargain buying after last week’s falls to three-year lows.

Wheat fell as continued cheap shipments from the Black Sea pressured prices.

Chicago Board of Trade most-active soybeans rose 0.4% to $11.89-1/4 a bushel by 1217 GMT. Corn rose 0.4% to $4.30-3/4 a bushel. Wheat slipped 0.8% to $5.92-1/4 a bushel.

Soybeans and corn last week hit three-year lows after the U.S. Department of Agriculture raised estimates of Brazil's last soybean harvest and said Argentina is facing a bumper crop, allaying fears of shortages.

“Corn and soybeans are seeing support from bargain buying after strong price falls last week but the overall market still looks weak after forecasts of large South American crops last week,” said Matt Ammermann, StoneX commodity risk manager.

“In the face of large South American crops, it is hard to see what arguments can be made for sustained price rises in corn and soybeans. The beneficial impact of late rains on Brazil’s soybean crop has yet to be fully assessed. Late season rains traditionally add soybean crop value in most countries.”

Demand from China and other Asian countries was expected to be low this week during the Lunar New Year holidays.

Wheat faced competition from cheap Russian prices.

“Wheat continues to see downward pressure from expectations large volumes of Russian wheat will have to be sold in coming months to free up storage space ahead of this summer’s harvest, with Russian prices still low,” Ammermann said.

“Demand is also slack with no major new purchase tenders issued so far this week by importers. Ukraine’s exports by sea continue to expand while the market has also shrugged off and is showing little concern about the report of an attack by Ukraine on a Russian civilian ship over the weekend. (Reporting by Michael Hogan in Hamburg, additional reporting by Peter Hobson in Canberra; editing by Janane Venkatraman and Susan Fenton)